Play video from Apple to TV
How can I play downoaded videos from my Mac Mini on my TV which is connected with an HDMI?
Mac mini, Mac OS X (10.7.5), 8 GB RAM. 500 HD, Bamboo Tablet
If you have a newer Mac and Apple TV 2 or later then you can use AirPlay
Apple TV: How to use AirPlay Mirroring
Otherwisn, if you have an Apple TV 2 or later and the moves are in your iTunes libary yo can use HOme Sharing